WELLINGTON, New Zealand  A magnitude 6.7 earthquake struck southern New Zealand early Tuesday, but police in the region said there were no immediate reports of injury or damage.

Two aftershocks later rattled the region.

The initial quake, which struck at sea 38 miles west of Milford Sound on South Island's west coast at 1:29 a.m. local time Tuesday, was some 15 miles beneath the surface, the New Zealand geological agency, GNS Science, reported on its Web site.

The Pacific Tsunami Warning Center in Hawaii said it did not expect the quake to generate a destructive tsunami.

Police senior sergeant Bruce Ross in the southern city of Dunedin said, "We felt it (here), but there are no reports of injury or damage."

"We heard the blinds rattle a bit, but that was it," he added.

Inspector Alan Weston in the southern city of Christchurch said about 10 people called shortly after the quake, but "we have no reports of damage or any injury," adding the sharp quake was "not felt in Christchurch."

New Zealand sits above an area of the earth's crust where two tectonic plates are colliding and records more than 14,000 earthquakes a year  but only about 150 are felt by residents. Fewer than 10 a year do any damage.